How many films do we need about nerds who think they're superheroes? We've already had Kick-Ass, Defendor and Special; now brace yourself for Super, in which greasy spoon chef Rainn Wilson has a psychotic breakdown when his wife (Liv Tyler) leaves him for a wealthy drug-dealer (Kevin Bacon at his sleaziest) and, with the help of imaginary brain-burrowing worms from outer space, transforms himself into – ta-da! – Crimson Bolt, a DIY "superhero" whose modus operandi is mostly crouching behind dumpsters, waiting for bad guys to walk past.

Super was part of the line-up at this year's Brussels International Fantastic Film Festival, better known as BIFFF. Highlights included Balada Triste, the new film from Alex de la Iglesia (part of the opening ceremony and thus out of bounds to low-ranking reporters like me), Jee-Woon Kim's I Saw the Devil (which won the festival's Golden Raven prize), Guillem Morales' giallo-esque woman-in-periller Julia's Eyes, Jim Mickle's lively vampire apocalypse-western road movie Stake Land (pictured), and Cesar Ducasse and Mathieu Peteul's no-budget Norwegian eco-horror Dark Souls, which features an army of driller-killers in orange boiler-suits and zombies bleeding oil instead of blood.

For the past few years, BIFFF has been held in The Sheds, part of a complex in the North West of Brussels called Tour et Taxis, which started life as a 19th century railway depot but now looks like Dartmoor Prison with a facelift, housing chic shops and restaurants, and playing host to cultural events. Despite ongoing development, it remains a rather inhospitable part of town, amid the sort of canalside industrial wasteland which puts a lone female pedestrian on her guard, especially late at night. But during BIFFF, the inside of The Sheds is transformed into genre-fan heaven, with DVDs, BDs, steampunk scupltures, body-painting and vast bar and restaurant areas stalked by unearthly creatures: huge Chinese dragons, a guy in a frock and feather boa with his moobs hanging out and, best of all, a giant eyeball on stilts which poked at me while I was queuing for a film.

Talking of queues, one of Crimson Bolt's early targets in Super is a guy who jumps a cinema queue and gets his head bashed in with a wrench. Serves him right! The writer-director is James Gunn, whose directing debut, Slither, was a genre-savvy monster-mash, but Super's over-the-top gore and sick sexual humour (one "highlight" is Wilson being raped by his nympho sidekick, played by a manic Ellen Page) is more reminiscent of films like Class of Nuke 'Em High, so it comes as no surprise to learn that Gunn used to work for Troma. Since them, he has written screenplays for Scooby-Doo and the remake of Dawn Of The Dead but, as Super shows, you can take the boy out of Troma, but you can't take the Troma out of the boy.

The Super screening was livened no end by input from spectators, who yelled smart-aleck comments at the screen and greeted each fresh outbreak of splatter with loud whistles. I'm told that yelling at the screen is a BIFFF tradition, so it pays to pick your screenings wisely. Barking-mad movies like the Finnish killer-Santa movie Rare Exports or André Øvredal's Troll Hunter may benefit from this sort of audience participation, but it was less welcome during, for example, John Carpenter's The Ward, in which the female characters were repeatedly regaled with shouts of "Slut!" and "À poil!" (French for "Get 'em off!"), or Hou Chi-Jan's chronology-shuffling One Day, a delicate Taiwanese tale in which two people meet, fall in love and are tragically parted by fate – but much too slowly for BIFFF's noisier patrons.